Imbolc - Candlemas or Brigids Day
Ostara - Spring Equinox
Beltane - For pagans I think this one is just Beltane... for Non-Pagans "Thats the Sex holiday, isn't it?"
Midsummer - Summer Solstice or Battle of the Holly & Ivy Kings
Lugnasadh - Harvest Festival
Mabon - Second Harvest Festival or Fall Equinox
Samhain- Night of Veils or Day of Dead
Yule- Winter Solstice or The Holly Kings Triumph

Or at least that what I've heard them refered to by various pagans here in Calgary.

Well don't know if that helped at all... We have some strange traditions here in Calgary though. I don't think I've ever heard of anybody calling them these secondary names outside of Calgary, and even here, they're becoming less used as people become more willing to actually spend time learning to pronounce these things.

Trying to create a world, even in words, is good occupational therapy for lunatics who think they're God, and an excellent argument for Polytheism. -S.M. Stirling

"If you trust in yourself and believe in your dreams and follow your star...you'll still get beaten by people who spent their time working hard and learning things and weren't so lazy. Goodbye." - Miss Tick, Terry Pratchett's Wee Free Men